Configuring Headlights for the ProtoThrottle

A common question about the ProtoThrottle is how to configure the headlights on a locomotive to work best with the throttle. The ProtoThrottle has two prototypical headlight switches, one for the front, the other for the rear.

Each switch can independently set the front and rear lights to one of four modes:

Off

Dim

Bright

Bright + Ditch Lights

The default configuration for most decoders works well for traditional throttles, but some changes are needed to take full advantage of the ProtoThrottle’s headlight switches. Four basic steps are needed to set up the decoder and the ProtoThrottle:

Make the Headlights Non-Directional
Most DCC decoders come pre-programmed for automatic directional headlights. With the two light switches on the ProtoThrottle, automatic front/rear operation is no longer needed or desired. Similarly, by default, both headlights are operated by function F0 and we need to change one of them to be controlled by a different function.

Configure the Headlights to be Dimmable
If not already set up by default, the dimmer function needs to be activated and assigned to the headlights. Some decoders only have a single dimmer and cannot independently dim both front and rear lights (i.e. one bright, the other dim). This is a limitation of the decoder not the ProtoThrottle.

Assign the Ditch Lights to Separate Functions
If the locomotive is equipped with ditch lights lit by bulbs separate from the headlights, they should be assigned to functions separate from each of the headlights.

Configure the ProtoThrottle
Both the front and rear headlights have 4 settings each in the Configure Function (CONFIG FUNC) menu of the ProtoThrottle. The functions names for the front headlight are prefixed with F while the function names for the rear headlight are prefixed with R. These functions are:
F.HEAD, R.HEAD: function set when Bright and Bright + Ditch are selected
F.DITCH, R.DITCH: function set when Bright + Ditch is selected
F.DIM #1, F.DIM#2, R.DIM #1, R.DIM#2: up to 2 functions that are set when Dim is selected

These steps are discussed in detail below, including examples for each decoder type. Some decoders have fewer configuration options and, as a consequence, cannot support all the modes that the ProtoThrottle allows. If your decoder type is not listed, have no fear, it is very likely similar to one of those below. And please let us know if you come up with a configuration for a decoder type not listed, or a better way of configuring one of the listed decoders.

NCE

While not sound equipped, the DCC decoders from NCE can still be configured for the ProtoThrottle. The following instructions are based on the 6-pin N12NEM decoder, but other models should be similar.

Step 1: Make the Headlights Non-Directional

For this example, we are going to assign the front headlight (output 1) to function F0 and the rear headlight (output 2) to function F1. Using the function mapping table in the decoder manual we can find the values to program into the CVs to accomplish this:

CV33 and CV34 should be programmed to a value of 1 while CV35 should be programmed to a value of 2. Note that, on this decoder, CV33 and CV34 operate identically and directionality is provided by the effects configuration for the output(s). Therefore, to remove directionality completely, we need to configure those.

CV120 configures the effects for output 1 (front headlight). CV121 does the same for output 2 (rear headlight). Referring again to the N12NEM manual:

For standard on/off headlights with no dimming, from the table, we start with a CV value of 0. Since we are using LEDs, we want the LED bit set (+128). To eliminate directionality, set the REV and FWD bits to 0. Therefore, program both CV120 and CV121 to a value of 128. To add dimming capability, continue reading…

Step 2: Configure the Headlights to be Dimmable

Fortunately, the NCE decoder provides two functions (F4 and F8) that can activate the dimmer. This allows the front and rear headlights to be dimmed independent from each other and achieve full ProtoThrottle compatibility. Referring to the effects configuration table above, the values for the effects configuration CVs are 32 and 36. We are going to use F4 to dim the front headlight and F8 to dim the rear headlight. The values for CV120 and CV121 are now:

CV120 = 128 + 32 = 160
CV121 = 128 + 36 = 164

Step 3: Assign the Ditch Lights to Separate Functions

Since I’m using an N-scale Fox Valley Models ES44C4 and the ditch lights are lit by the same light tube as the headlights, I’m limited by the hardware and cannot do this. However, even on the N12NEM decoder, outputs 3 and 4 also available as solder pads. Someday I’ll wire them up to LEDs, and cut the light tubes going to the ditch lights, so I can independently control the ditch lights. But that’s a project for another day…

If outputs 3 and 4 were connected to lights for the ditch lights, then I’d configure them to be controlled by separate functions from the headlights. For the sake of argument, let’s say we wired output 3 to the front ditch lights and we want to control it with F3. Output 4 is wired to the rear ditch lights and we want to control it with F4. Looking again at the function mapping table from the N12NEM decoder manual:

We program CV37 with a value of 4 so that function F3 controls output 3. Program CV38 with a value of 1 so that function F4 controls output 4. Now the front and rear ditch lights can be turned on and off using functions F3 and F4, respectively, independent from each other and independent from the front and rear headlights. The effects configuration CVs for outputs 3 and 3 (CV122 and CV123) should also be programmed to a value of 128 (LED + standard on/off + no directionality).

Step 4: Configure the ProtoThrottle

Now that we have the locomotive configured properly, the final step is to tell the ProtoThrottle how to control those lights. Start by going to the CONFIG FUNC menu. We are going to change eight settings, four for the front headlight and four for the rear:

In this example, I am using DecoderPro, which is part of JMRI, to configure a TCS WOWDiesel decoder. By default the headlights (both front and rear) as assigned to F0, but are directional – turning on automatically in the direction the locomotive is headed. We will start by assigning the front headlight to function F0 and the rear headlight to function F3. Using the Function Map tab in DecoderPro, assign both F0 inputs to output wire 1 (white, front headlight) and the F3 input to output wire 2 (yellow, rear headlight):

On the Lights tab, change the White Wire Timing and Yellow Wire Timing to “Function on both directions”. This eliminates the automatic directionality of the lights so that they follow what the ProtoThrottle light switches are telling them to do, not the locomotive’s direction of travel. However, we’re not quite done yet…

The TCS decoder has a concept of light mode vs. sound mode. This lets you use the same function keys to control both lights and sounds, depending on which mode the decoder is in at any given moment. However, for the ProtoThrottle, we need the light functions to work in either mode. Therefore, we need to configure the functions associated with the lights to be “dual mode”. We also need to remove the sounds associated with them so the sounds don’t activate when we turn the headlights on or off! On the Sound Function tab in DecoderPro, make sure the “Dual function” checkboxes for both F0 and F3 are checked:

On the same tab, set the Function 0 Sound and Function 3 Sound to “None”. Now the front and rear headlights are selectable, independent from the direction of travel, using unique functions F0 and F3.

Step 2: Configure the Headlights to be Dimmable

To make the lights dimmable, we need to set the effect for the outputs to “Rule 17”. By default, this makes them button dimmable – dimmed when a particular function is activated. On the Lights tab in DecoderPro, select Rule 17 in the White Wire Effect and Yellow Wire Effect boxes:

The TCS decoder has a single dimmer, by default assigned to function F4. Since decoder only has a single dimmer, you cannot have one headlight dim while the other is bright. For example, if the front headlight is bright, and you set the rear headlight to dim, both headlights will be dim because the dimmer is activated.

As before, we need the dimmer function (F4) to be active in both modes of operation and have no sound assigned to it. Using the Sound Function tab, check the checkbox next to “Dual function F4” and set the Function 4 Sound to “None”.

Finally, the brightness of the dim setting can be adjusted. Back on the Lights tab, change the “Constant Dim 1 Brightness” until you have the dim setting you like. In this case, a value of 15 was found to be good:

Step 3: Assign the Ditch Lights to Separate Functions

We are going to use F9 and F10 to control the front and rear ditchlights, respectively. On this particular locomotive, the front ditchlights are connected to output wire 3 (green) and the rear are connected to output wire 4 (purple). Similar to what we did with the headlights, F9 and F10 should be mapped to output wire 3 and output wire 4 using the Function Map tab in DecoderPro:

On the Lights tab, make sure the Green and Purple Wire Effects are set to “Constant bright light” and the Timing settings are “Function on both directions”.

Remove the sounds associated with F9 and F10 using the Sound Function tab (set them to “None”) and check the Dual function checkboxes for F9 and F10:

Step 4: Configure the ProtoThrottle

Now that the locomotive is configured properly, the final step is to tell the ProtoThrottle how to control the lights. Start by going to the CONFIG FUNC menu. We are going to change eight settings, four for the front headlight and four for the rear:

In this example, we will assign the front headlight to function F0 and the rear headlight to function F19. Each effect has a dedicated CV whose value determines the function that controls the effect.

The front headlight is CV1.257 and the rear headlight is CV1.258. Set CV1.257 to a value of 0 (F0) and CV1.258 to a value of 19 (F19). This gives the front and rear headlights independent controls. To make them non-directional, the direction enable CVs must also be set. CV57 controls which functions are enabled in the forward direction and CV58 does the same for the reverse direction.

Bits BL (value = 2) and HL (value = 1) should both be set in CV57 and CV58. This allows the front and rear headlights to be active in both the forward and reverse directions, allowing the functions assigned to them (F0 and F19) to be the only things that control whether the lights are on or off.

Step 2: Configure the Headlights to be Dimmable

The Tsunami2 decoder has a single dimmer, by default assigned to function F7. By selecting the appropriate Hyperlight effect for the headlights, the dimmer can be used to dim the light. CV49 is used to configure the front headlight effect whereas CV50 configures the rear headlight effect. A value of 1 selects a standard dimmable headlight which immediately transitions to the new brightness. A value of 15 selects a Dyno-Light with soft fading between brightness levels. If using LED bulbs, add 128 to those values.

Since the Tsunami2 decoder only has a single dimmer, you cannot have one headlight dim while the other is bright. For example, if the front headlight is bright, and you set the rear headlight to dim, both headlights will be dim because the dimmer is activated. One partial workaround is to only allow one headlight to be dimmed. Change the effect for the other headlight to a standard on/off output (value = 0). Say, for example, we want the front headlight to be dimmable, but are willing to forgo dimming on the rear headlight, set CV49 = 1 or 15 as above but CV50 = 0 (standard on/off output). This way, whenever the front headlight is dimmed, the rear headlight will be bright (or off).

The above restriction does not apply in a multiple unit consist. In that case, since the front and rear headlights are controlled by separate decoders, they can be independently dimmed. Just configure the opposite headlight to always be off.

Step 3: Assign the Ditch Lights to Separate Functions

For this example, the front ditch lights are connected to outputs FX3 and FX4. The rear ditch lights are connected to outputs FX5 and FX6. We are going to use function F5 to control the front ditch lights and function F6 to control the rear ditch lights. As with the headlights, each output has a CV that determines the function assigned to it:

FX3 = CV1.259
FX4 = CV1.260
FX5 = CV1.261
FX6 = CV1.262

Set CV1.259 and CV1.260 to a value of 5 (F5). Set CV1.261 and CV1.262 to value of 6 (F6). Also be sure to set the corresponding bits (FX3, FX4, FX5, FX6) in CV57 and CV58 to make both pairs of ditch lights non-directional. For this example, CV57 and CV58 should both be set to a value of 63.

Step 4: Configure the ProtoThrottle

Now that the locomotive is configured properly, the final step is to tell the ProtoThrottle how to control the lights. Start by going to the CONFIG FUNC menu. We are going to change eight settings, four for the front headlight and four for the rear:

The example below uses the free LokProgrammer software from ESU to set up the decoder configuration. Even if you do not have a LokProgrammer, you can still use the free software to generate your configuration, then export the list of CVs for manual programming. Either use Tools -> Export CV list… to get a list of all the CV values or Tools -> Show changed CVs… to see just those CVs that were changed.

Step 1: Make the Headlights Non-Directional

The headlights for this Intermountain GP10 came programmed as automatically directional, controlled by function F0:

Note: the AUX2 output is being used as the front headlight. The Front Light output on this decoder is being used as a gyralight and is not considered the headlight in this case.

To remove the directionality from the headlights, configure them as follows (go to the Function Mapping tab of the LokProgrammer software):

This makes F0 control the front headlight and F5 control the rear headlight. Notice that the “Forward” and “Reverse” conditions were removed. This way the light obeys only the function, regardless of the direction the locomotive is moving. F5 was chosen somewhat arbitrarily here – you can use any unused function.

Step 2: Configure the Headlights to be Dimmable

In the Loksound decoder, as with many other decoders, there is only one function-activated dimmer. This can be found under the Logical Function column. However, we’re not going to use that here as it complicates getting the headlights independently dimmable (it can be done, but it’s not as clean). What we’re going to do instead is to use the two “pseudo-outputs” for each of the headlights. If you look closely, you’ll notice the AUX2 output has 2 versions available: AUX2 [1] and AUX2 [2].

Internal to the decoder, these are treated as separate function outputs. However, they control the same physical output on the decoder. Effectively, this gives us two independent paths in which to turn on the AUX2 output. The Rear Light output has the same thing. One path will be used for a full brightness headlight while the other will be used for a dim headlight. We are going to use F3 to enable the dim front headlight and F6 to enable the dim rear headlight (again, the function numbers are somewhat arbitrary).

This alone, however, won’t give you dim headlights when F3 and/or F6 are activated. We also need to configure the outputs themselves. This is done in the Function Outputs tab. Select the AUX [2] output (the one assigned to F3 above) and adjust its brightness to a lower level. Some experimentation may be needed to achieve the brightness level you want for a dim headlight. Do the same for the Rear Light [2] output (the one assigned to F6 above).

For the output mode on all four outputs (AUX2 [1], AUX2 [2], Rear Light [1], Rear Light [2]) you’ll want to select Dimmable Headlight, not Dimmable Headlight (Fade In/Out). Fading doesn’t work well when transitioning between the two output (e.g. AUX2[1] to AUX2[2]) because the light fades all the way to off before fading back up to the new brightness level. This causes it to blink. With the Dimmable Headlight setting (no fading) you lose the fade effect, but don’t have to put up with the blink. This might be a matter of personal opinion, so feel free to experiment.

Step 3: Assign the Ditch Lights to Separate Functions

Now that the headlights are configured properly, assign functions to control the ditch lights. In this example, the ditch lights are wired to AUX1 (front) and AUX4 (rear). We’re going to use F4 to control the front ditch lights and F7 to control the rear ditch lights:

Now that the locomotive decoder configuration is complete, if you are using a LokProgrammer, write the configuration using the Programmer -> Write decoder data menu option. If not using the LokProgrammer, you can export the list of changed CVs using the Tools -> Show changed CVs… menu item and program the CVs manually using your DCC system.

Step 4: Configure the ProtoThrottle

The final step is to tell the ProtoThrottle how to control the lights. Start by going to the CONFIG FUNC menu. We are going to change eight settings, four for the front headlight and four for the rear:

Comments

My prototype The Wisconsin Central had directional front and rear ditch lights. It appears by this example that by the time you get everything dimmable you may not have enough function keys left for loksound motor controls? Yes/No

I’m not sure I understand the question, specifically what you mean by “loksound motor controls”. Controlling the speed and direction of the motor doesn’t require any functions. Additionally, the ProtoThrottle can access all 29 standard DCC functions. That, combined with the LokSound flexibility in mapping functions, you will be hard pressed to run out of functions even with fully independent and dimmable front and rear head lights and ditch lights.

May not have stated my question well. After I asked the question I realized I am thinking from a NCE throttle point of view.( ie buttons to push) Then I realized there are no buttons on this and they will be handled in the PT configuration files. I plan to use the PT with existing NCE throttles I have. My trains are heavy and long and I am trying to figure out how to maximize function mapping to utilize FT features. Maybe one of your NCE beta testers could chime in on how they went about this? It would be appreciated if that were possible. I am trying to set up a set of locals that are properly configured when the PT’s arrive in a few weeks!

THIS SYSTEM IS MORE COMPLEX FOR HORN AND BELL SET UP LIGHTING IS HARD TOO. I HAVE ASKED THEM TO CALL ME SEVERAL TIMES, THEY HAVE NOT CALLED ME. I AM READY TO SEND THIS UNIT BACK FOR A REFUND. REALLY FRUSTATED WITH IT. I HAVE E MAILED THEM THEY DO RESPOND STILL NOT MUCH HELP. UNIT OPERATES TRAINS GOOD. I CANNOT GET MY HORN LEVER TO WORK AND THE BELL BUTTON DOES NOT RESPOND. I HAVE ALL SET TO F 1 BELL, F2 HORN, ETC. STILL DOES NOT RESPOND. ANY HELP OUT THERE. RON BROOKS

Well I just gotta say a big KUDOS to the guy in Iowa from the team , he called me solved my dilemma on the phone. Now my frustration has been eased up all works good now. Next hurdle lighting functions.